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Retirement Plans (Accumulated and Projected Benefit Obligations) (Details) - USD ($) $ in Millions | Sep. 30, 2019 | Sep. 30, 2018
--- | --- | ---
Pension Plans with accumulated benefit obligations in excess of plan assets |  |
Projected benefit obligation | $ 356.6 | $ 6.3
Accumulated benefit obligation | 356.6 | 6.3
Fair value of plan assets | 351.6 | 5.0
Pension plans with plan assets in excess of accumulated benefit obligations |  |
Projected benefit obligation | 0.0 | 327.1
Accumulated benefit obligation | 0.0 | 327.1
Fair value of plan assets | $ 0.0 | $ 338.5

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- Definition Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2417-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2417-114920 + Details
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